The 120mm rounds will be used to arm the 31 M1A1 Abrams tanks which Washington plans to deliver to Ukraine in the autumn.
The move - part of a new military aid package worth up to $175million (£140m) - follows Britain’s decision to send the controversial armour-piercing rounds to Kyiv in March, alongside Challenger 2 tanks.
The munitions are controversial as they include depleted uranium, which is a byproduct of the uranium enrichment process needed to create nuclear weapons. The rounds retain some radioactive properties, but they can’t generate a nuclear reaction like a nuclear weapon would.
The new security package for Ukraine was announced during US secretary of state Antony Blinken’s visit to Kyiv yesterday.
“This new assistance will help sustain it and build further momentum,” Mr Blinken said.
Ukraine has so far made only small territorial gains in its counter-offensive. But Ukrainian generals claimed this week to have breached Russia’s first line of defences in the south of the country.
Russia said the US supply of depleted uranium weapons to Ukraine was “a criminal act” and an “escalatory step”.
Mr Blinken’s visit was overshadowed by a Russian missile strike on an outdoor market which killed 17 people and wounded dozens.
The attack on the town of Kostiantynivka, near the front line in the Donetsk region, turned the marketplace into an inferno and was one of the deadliest bombardments of civilians in the 18-month-old war.
Police said the market had been crowded when it was hit at around 2pm local time, and that nearly 30 shopping kiosks, an apartment block, a bank and cars were damaged.
Video taken by The Associated Press showed a chaotic scene, with charred bodies lying on the ground, some of them still burning.
Ukraine’s President Volodymyr Zelensky said the strike was deliberate.
“Whenever there are any positive advances by Ukrainian defence forces in that direction, Russians always target civilian people and civilian objects,” he said.
Russian state media today reported a wave of Ukrainian drone attacks on its territory.
Drones were downed near Moscow, in southern Rostov and the Bryansk region in the southwest in the early hours, the RIA news agency said.
According to another news agency, TASS, three buildings were damaged in the city of Rostov-on-Don and one person was injured when one of the drones crashed in the downtown area.